Certain cleaning operations, particularly those involving cleaning of commercial and institutional ceilings and walls, are often performed by professional cleaners using specialized equipment designed for the task. Clearly, such equipment has a significant impact upon the thoroughness of the cleaning operation and upon the ease and efficiency with which workers perform it. And the equipment must be reliable--failures and downtime are disruptive.
While the products of earlier designers of cleaning tools have been generally satisfactory, they are characterized by certain disadvantages. For example, in a tube-like extendable device, a way to provide pressurized liquid from its proximal end to the nozzle at the distal end is to fill the entire device with such liquid. In effect, the device becomes its own hose.
For telescoping devices, so-called "dynamic" seals (e.g., sliding or rotating seals) are required to seal in liquid and avoid leaks even though device components move with respect to one another. Such seals are significantly more complex than static seals.
Where the device includes rigid, telescoping tubes providing the user with a substantial "reach," the weight of the confined liquid becomes significant. The user is apt to tire more quickly. And device disassembly and storage becomes a problem since it must first be emptied of liquid.
Another disadvantage of some prior art tools is that they fail to recognize that tool users may clean areas very near by or at some considerable distance away. Certain of such tools fit one situation or the other--but not both.
Examples of prior art tools (not necessarily having the above-noted deficiencies) are described in the following patents. U.S. Pat. No. 4,202,068 (Lester) shows a pneumatically-powered scrubbing tool fed by a straight length of compressed air supply hose. An extension support pole fits over the main support pole and can be extended to a preselected position. The entire extension pole is rotated to lock relative pole positions.
U.S. Pat. No. 4,989,295 (Guhne et al.) describes a telescopic wand having a short, coiled internal electrical cable which accommodates extension. The two tubes can be positionally adjusted one to the other in steps.
U.S. Pat. No. 4,270,238 (Shallenberg et al.) shows a cleaning tool particularly adapted to ceiling and wall cleaning. The tool is a "dual-path" structure in that it applies a cleaning liquid through a brush and almost immediately after application, draws dirty liquid away using a vacuum-induced air stream.
U.S. Pat. No. 3,881,209 (Reinitz et al.) shows a machine for spray cleaning ceiling tiles by feeding them through the machine after they are removed from their mounting grids.